LAMS (Los Angeles Motor Scale) Calculator

Los Angeles Motor Scale (LAMS): Explanation and Clinical Context The Los Angeles Motor Scale (LAMS) is a rapid prehospital stroke assessment tool designed to predict the likelihood of a large vessel occlusion (LVO) in patients presenting with acute neurological deficits. It evaluates three motor domains: facial droop, arm drift, and grip strength. Each domain is scored individually (Facial: 0–1; Arm: 0–2; Grip: 0–1), yielding a total score ranging from 0 to 5.

Higher scores indicate more severe motor deficits and higher probability of LVO. Clinically, LAMS is used by EMS to triage patients, determining whether they should be transported directly to a comprehensive stroke center capable of performing mechanical thrombectomy. LAMS has been validated to reliably predict anterior circulation LVO in the prehospital setting and helps reduce treatment delays.